>>18666
The original flag has to be hidden, then the background to be fit to its place. Something like:

background-repeat: no-repeat !important;
width: 0px !important;
height: 12px !important;
padding-right: 17px;

The width hides the original flag.
The height and the padding-right gives space for the background image (the new flag) to appear.
The height will regulate the vertical position of the flag.
I think the original flag size is 16x11 pixels, but 17x12 might be needed to look right. Has to be tested.
Background-repeat has to be turned off.
!important might or might not be needed.